Question

Mensuration Cube and Cuboid
1.
A cuboid has three mutually perpendicular edges measuring 5 cm, 4 cm and 3 cm. Find (i) its volume, (ii) its total surface area, and (iii) the length of the diagonal.
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Answer 1

Here,

l=5 CM

b=4 CM

h=3 CM

then,

volume of the cuboid= l×b×h

(5×4×3) CM

60 cm^3

again,

total surface area of cuboid=2×(lb+bh+lh)

2×(5×4+4×3+5×3)

2×(20+12+15)

2×(47)

94 cm^2

I hope that you will get you answer.

Answer 2

Given:

Length of the cuboid = 5 cm

Breadth of the cuboid = 4 cm

Height of the cuboid = 3 cm

Calculating:

(i) Volume of the cuboid

Formula that we use to find the volume of a cuboid:

= Length x Breadth x Height

Substituting values known to us in this formula we get:

= 5 x 4 x 3

= 20 x 3

= 60 cm^3

Therefore, the volume of the cuboid is 60 cm^3.

(ii) Total Surface Area

Formula that we use to find the total surface area of a cuboid:

= 2(lb + lh + bh)

Substituting all the values known to us in this formula we get:

= 2((5)(4) + (5)(3) + (4)(3))

= 2(20 + 15 + 12)

= 2(47)

= 94 cm^2

Therefore, the volume of the cuboid is 94 cm^2.

(iii) Length Of Diagonal

Formula that we use to calculate the diagonal of a cuboid:

= √(l^2+b^2+h^2

Substituting all the values known to us in this formula we get:

= √(5)^2 + (4)^2 + (3)^2

= √25 + 16 + 9

= √50 cm

Therefore, the length of diagonal of the cuboid is √50 cm.